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Transition Metal Carbide Core/Shell Nanoparticles by Ultra-Short Laser Ablation in Liquid
摘要： Transition metal carbide nanoparticles are a class of technological interesting materials with a wide range of applications. Among metal carbides, tantalum carbides have good compatibility with the biological environment while molybdenum carbides are used as catalyst in electrochemical reactions. Laser ablation of bulk transition metal targets in some liquids is here reported and laser ablation in organic solvents is used as simple synthetic strategy for the production of carbide nanostructures. Herein, the nanoparticles produced by ultra-short laser ablation of tantalum and molybdenum in water, acetone, ethanol and toluene have been characterized by TEM, XRD and XPS analysis. The combined effect of metal and solvent chemical and physical properties on the composition of the nanomaterials obtained has been pointed out. In particular, the different reactivity of Ta and Mo with respect to oxidizing species determines the composition of particles obtained in water, on the other hand the organic solvents decomposition allows to obtain transition metal carbide (TMC) nanoparticles. The observed carbonaceous shell formed on TMC allows to protect the particle’s carbidic core and to improve and tailor the applications of these nanomaterials.
关键词： ultrashort laser ablation in liquid,transition metal carbide,core/shell nanostructures,solvent degradation
更新于2025-09-19 17:13:59
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Synthesis and Characterization of Aluminum Nanoparticles Prepared in Vinegar Using a Pulsed Laser Ablation Technique
摘要： The second harmonic wavelength of a neodymium-doped yttrium-aluminum-garnet (Nd-YAG) laser (λ = 532 nm) was used in a pulsed laser ablation technique (PLAL) to synthesize aluminum nanoparticles suspended in white vinegar from an aluminum target. The nanoparticles were characterized by HRTEM and UV-Vis spectrophotometry. They were found to range in size between 2 and 50 nm in diameter, with an average diameter of 12 ± 9 nm. The nanoparticles had a maximum absorption peak at 237 nm and were found to exhibit a core-shell structure with an Al core coated by a thin layer of an amorphous material which could be attributed to amorphous carbon. HRTEM results revealed that the small nanoparticles (<20 nm) had an fcc phase of aluminum crystalline structure, where the larger particles represented alumina (γ-Al2O3) nanoparticles. Such observation suggests that the use of white vinegar as an ablation medium could facilitate the synthesis of aluminum nanoparticles with minimal evidence of the existence of aluminum oxide nanoparticles in the resultant suspension.
关键词： pulsed laser ablation in liquid (PLAL),UV-Vis spectrophotometry,white vinegar,HRTEM,Aluminum nanoparticles
更新于2025-09-19 17:13:59
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Laser-induced anchoring of WO3 nanoparticles on reduced graphene oxide sheets for photocatalytic water decontamination and energy storage
摘要： In this work, the synthesis of tungsten oxide/reduced graphene oxide (WO3-rGO) nanocomposite, using a simple method of pulsed laser ablation in liquids (PLAL) is reported. The pulsed laser beam of 355 nm wavelength carries out two simultaneous processes: the reduction of graphene oxide and at the same time the anchoring of nanostructured WO3 on reduced graphene oxide. In the photo-catalytic application, WO3-rGO shows much better visible light absorption and less photo-generated charge recombination than pure WO3, as indicated by optical absorption and photoluminescence spectra. These improved features in WO3-rGO significantly enhanced the photo-catalytic decontamination of methylene blue (MB) dye in the water, compared to the use of pure WO3 as a photocatalyst. A Poly 2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS) based electrolyte together with the high electrical conductance and porosity of rGO which were produced after anchoring WO3 on the graphene oxide, were harnessed for the energy storage application using this material for a supercapacitor. The specific capacitance for WO3-rGO based device is achieved to be 577 F g?1 measured by the galvanostatic charge-discharge (GCD) method. Also, at a power density of 1000 W kg?1, the as-synthesized WO3-rGO demonstrated a large energy density value of 76.3 Wh Kg?1 that is much larger than obtained, using WO3 alone. Besides these photocatalytic and energy storage performance evaluation of WO3-rGO, the optical, morphological and elemental characteristics of synthesized WO3-rGO were also investigated to study the improved performance of the nanocomposite in these two applications.
关键词： PAMPS,Supercapacitor,Pulsed laser ablation in liquid,Energy storage,Photo-catalytic decontamination
更新于2025-09-16 10:30:52
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Controlled Nitrogen Doping of Graphene Quantum Dots Through Laser Ablation in Aqueous Solutions for Photoluminescence and Electrocatalytic Applications
摘要： Nitrogen-doped graphene quantum dots (N-GQDs) have promising applications in catalysis and photoluminescence, but many existing synthetic methods require uses of harsh chemicals, long reaction times, and complicated purification steps and have poor control over the surface functional groups. Laser ablation in liquid (LAL) is a promising alternative method to prepare nanomaterials because of its fast production, use of fewer chemicals, simple purification, and fewer byproducts and its control of the product by precise tuning of laser ablation parameters. We report the use of LAL to produce N-GQDs from carbon nano-onions in aqueous solutions of ammonia, ethylenediamine, and pyridine. The choice of these dopants allowed for tuning the overall nitrogen content and the distribution of functional groups that led to the control over the photoluminescence emission wavelengths and lifetimes. High concentrations of amine groups tended to red shift emission and exhibit shorter lifetimes, whereas pyridinic groups would blue shift the emission and exhibit longer lifetimes. The N-GQDs also showed a promising performance as electrocatalysts for reducing oxygen to hydrogen peroxide, an important chemical widely used in industrial applications. The N-GQDs exhibited both low overpotentials and high selectivity for a two-electron oxygen reduction pathway.
关键词： electrocatalysis,photoluminescence,lifetime,laser ablation in liquid,oxygen reduction reaction,Graphene quantum dots
更新于2025-09-16 10:30:52
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Preparation of silicon naphthalocyanine nanoparticles by laser ablation in liquid and their optical properties
摘要： Silicon naphthalocyanine nanoparticles were successfully prepared by laser ablation in liquid. Silicon 2,3-naphthalocyanine bis(trihexylsilyloxide) powders in deionized water were irradiated with nanosecond-pulsed laser (Nd:YAG, SHG) to prepare nanoparticles. The prepared nanoparticles were investigated by scanning electron microscopy, dynamic light scattering and spectrophotometry. The shape was polygonal and partially spherical. The primary and secondary particle sizes were reduced with an increase in laser fluence. Absorbance was increased at low laser fluence and was constant at high laser fluence with the increase in laser fluence. The ratio of the two absorbance peaks was changed with the increase in laser fluence.
关键词： optical properties,laser ablation in liquid,nanoparticles,photoacoustic imaging,silicon naphthalocyanine
更新于2025-09-12 10:27:22
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Laser‐Ablation Produced Cobalt‐Nickel Phosphate with High‐ValenceNickel Ions as Active Catalyst for Oxygen Evolution Reaction
摘要： Cost-effective, highly efficient and stable non-noble metal-based catalysts for oxygen evolution reaction (OER) are very crucial on energy storage and conversion. Here, we report an amorphous cobalt-nickel phosphate (CoNiPO4) containing considerable amount of high-valence Ni3+ specie as an efficient electrocatalyst for OER in alkaline solution. The catalyst was converted from Co-doped Ni2P through pulsed laser ablation in liquid (PLAL) and exhibits a large specific surface area of 162.5 m2/g and a low overpotential of 238 mV at 10 mA/cm2 with a Tafel slope of 46 mV/dec, being much lower than those of commercial RuO2 and IrO2. Our work demonstrates that PLAL is a powerful technology for generating amorphous CoNiPO4 with high-valence Ni3+, thus paving a new way towards highly effective OER catalysts.
关键词： OER,high valence state,cobalt-nickel phosphate,Pulsed laser ablation in liquid
更新于2025-09-12 10:27:22
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Sensitive and Reproducible Gold SERS Sensor Based on Interference Lithography and Electrophoretic Deposition
摘要： Surface-enhanced Raman spectroscopy (SERS) is a promising analytical tool due to its label-free detection ability and superior sensitivity, which enable the detection of single molecules. Since its sensitivity is highly dependent on localized surface plasmon resonance, various methods have been applied for electric ?eld-enhanced metal nanostructures. Despite the intensive research on practical applications of SERS, fabricating a sensitive and reproducible SERS sensor using a simple and low-cost process remains a challenge. Here, we report a simple strategy to produce a large-scale gold nanoparticle array based on laser interference lithography and the electrophoretic deposition of gold nanoparticles, generated through a pulsed laser ablation in liquid process. The fabricated gold nanoparticle array produced a sensitive, reproducible SERS signal, which allowed Rhodamine 6G to be detected at a concentration as low as 10?8 M, with an enhancement factor of 1.25 × 105. This advantageous fabrication strategy is expected to enable practical SERS applications.
关键词： laser interference lithography,electrophoretic deposition,gold nanoparticle array,surface enhanced Raman spectroscopy,pulsed laser ablation in liquid
更新于2025-09-10 09:29:36